The invention relates to a control method for an internal combustion engine, in particular a Diesel engine, comprising an exhaust gas post-treatment system and a system for recirculating exhaust gases to the intake, the engine changing from a regeneration mode operation with throttling to a normal mode without throttling.
To meet emission control standards, internal combustion engines are equipped with post-treatment systems which trap and convert certain chemical compounds contained in the exhaust gases. Some post-treatment systems use an internal regeneration phase during which the operation of the engine is changed in order to establish favorable thermal and chemical conditions in the post-treatment system. These specific conditions promote the conversion of the chemical compounds which have been trapped in the post-treatment system.
These favorable conditions are usually obtained by reducing the performance of the engine by partial closing of the air intake circuit, which increases, particularly, the temperature of the exhaust gases.
Once the regeneration phase has passed, the aim is to open the air intake circuit as quickly as possible to limit the over-consumption of fuel and the transient production of certain chemical compounds contained in the exhaust gases.
However, for reasons of efficiency, these regeneration programs use high degrees of intake duct closure which create a significant reduction of the noise of the air intake circuit for the whole duration of the process.
At the end of the regeneration, by rapidly opening the intake ducts, the noise suddenly becomes loud again without the driver having changed the acceleration signal of the vehicle, which disturbs the auditory comfort of the occupants and may monopolize their attention.